Effects of changes in the criteria for nationally shared kidney transplants for HLA-matched patients.
BACKGROUND
Nine years ago, a prospective trial began in all U.S. transplant centers to determine whether the results of renal transplantation would improve with the nationwide shipment of kidneys from cadaveric donors to HLA-matched patients. Since then, the stringency of criteria for HLA matching have been liberalized twice, from sharing only those kidneys that matched at all six HLA-A, -B, -DR antigens, to sharing phenotypically HLA-matched kidneys, and most recently to sharing zero HLA-mismatched kidneys.


METHODS
Data reported to the United Network for Organ Sharing Scientific Renal Transplant Registry from October 1987 to December 1996 were analyzed to examine the transplant results of nationally shared HLA-matched kidneys and the effects of changes to the HLA matching criteria on graft survival and the distribution of HLA-matched kidneys.


RESULTS
The overall 1-year graft survival rate of 5102 HLA-matched transplants was 88% compared with 81% for 58,207 recipients of kidneys with at least one HLA mismatch (P < 0.001). HLA-matched kidneys had a projected 12-year graft half-life, 50% higher than the 8-year half-life of mismatched grafts (P < 0.01). After the first change in the match criteria in August 1990, 1365 phenotypically matched kidneys with fewer than six HLA antigens identified had an 89% 1-year graft survival rate compared with 84% for 466 six antigen-matched kidneys transplanted before the change. After March 1995, 1067 zero HLA-mismatched kidneys that were not phenotypically identical nor six antigen matched, had a 1-year graft survival rate of 88%. Graft survival has not decreased as a result of these changes in the criteria for national sharing, despite an increase in the percentage of matched transplants from 2.5% during the six antigen-match era to 15.5% during the zero antigen-mismatch era.


CONCLUSIONS
Changes to the United Network for Organ Sharing policy for national sharing of HLA-matched kidneys have increased the number of patients, and especially minority patients, who can benefit by receiving a well-matched graft without compromising the high graft survival rates provided by an HLA-matched kidney.
Hata
Y
Y
UCLA Tissue Typing Laboratory, Department of Surgery, University of California, Los Angeles 90095, USA.
Cecka
J M
JM
Takemoto
S
S
Ozawa
M
M
Cho
Y W
YW
Terasaki
P I
PI
D002102:Cadaver; D006085:Graft Survival; D006680:HLA Antigens; D006648:Histocompatibility; D006650:Histocompatibility Testing / Q000592:standards*; D006801:Humans; D016030:Kidney Transplantation / Q000276:immunology / Q000592:standards*; D010641:Phenotype; D009927:Tissue and Organ Procurement / Q000592:standards*; D014481:United States
D006680:HLA Antigens